This invention relates to optical switches and is particularly related to fast acting compact optical switches for communications and other fields
A variety of fiber optic switches have been produced or proposed primarily for optical communications These switches rely on conventional nematic liquid crystals and are generally arranged in devices in which the optical signal contacts the crystal at an oblique angle. While these conventional devices have permitted successful optical switching they have some significant drawbacks.
The most serious problem with conventional optical switches is that they are relatively slow. While optical communications networks would appear to have great advantages over electronic networks, the conventional nematic switches can only operate in the range of 1-100 milliseconds which limits network speed. The second serious Problem with conventional liquid crystal switches is the geometric arrangements required for successful switching take up considerable space. Specifically, use of oblique incidence light requires relatively long switching arrangments.
Yet another problem with conventional optical switches is a lack of memory and numerous stability states. Unpowered nematic type switches may quickly become disordered and thus fail to direct optical signals according to the most recently selected path. In other words, such conventional switches do not have a memory and if left unpowered may give haphazard and undesired results.
In view of the above, a need exists for a fast acting optical switch that will increase the operating speeds of fiber optic networks.
A further need exists for a compact optical switch that allows further miniaturization of optical components.
Yet another need exists for a stable optical switch that continues to direct optical signals along a preselected path after removal of an activating signal.